/usr/include/GNUstep/ is in cynthiune.app 0.9.5-14build1.
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/usr/include/GNUstep/Cynthiune
/usr/include/GNUstep/Frameworks/
/usr/include/GNUstep/Frameworks/Cynthiune.framework/
/usr/include/GNUstep/Frameworks/Cynthiune.framework/Headers
/usr/include/GNUstep/Frameworks/Cynthiune.framework/Versions/
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/usr/include/GNUstep/Frameworks/Cynthiune.framework/Versions/0/Format.h
/usr/include/GNUstep/Frameworks/Cynthiune.framework/Versions/0/MailService.h
/usr/include/GNUstep/Frameworks/Cynthiune.framework/Versions/0/NSArrayExtensions.h
/usr/include/GNUstep/Frameworks/Cynthiune.framework/Versions/0/NSCellExtensions.h
/usr/include/GNUstep/Frameworks/Cynthiune.framework/Versions/0/NSColorExtensions.h
/usr/include/GNUstep/Frameworks/Cynthiune.framework/Versions/0/NSNumberExtensions.h
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/usr/include/GNUstep/Frameworks/Cynthiune.framework/Versions/0/NSViewExtensions.h
/usr/include/GNUstep/Frameworks/Cynthiune.framework/Versions/0/Output.h
/usr/include/GNUstep/Frameworks/Cynthiune.framework/Versions/0/Preference.h
/usr/include/GNUstep/Frameworks/Cynthiune.framework/Versions/0/utils.h